Two sisters of late rock icon Prince have threatened to take legal action after reporting that truckloads of their brother's archival material, including unheard master tapes, have been removed from his Paisley Park studio complex. Sharon and Norrine Nelson have accused estate managers Comerica Bank & Trust of “extraordinary and unconscionable” behavior.

Prince had built up the archive at his Minnesota base over 40 years, and it’s thought to be the most valuable element of his estate, which has been valued at up to 200 million dollars in court papers. Canoe.com reported that Sharon Nelson had been told by a “Paisley Park representative” that four trucks had arrived in early September and emptied the vault. She said: “It’s just as though Prince passed away again. That’s how I felt. I was really devastated by that.” She added: “We want the music back home in Paisley Park where it belongs.”

The legal process over the estate continues, after Prince left no will when he died of an accidental painkiller overdose in April 2016. Comerica have been acting as the estate’s representative or executor, with two parties at odds over its ownership. One consists of the Nelson sisters and their brother John, and the other includes Prince’s full sister Tyka Nelson and half-brothers Omarr Baker and Alfred Jackson.

Under rules imposed by Carver County District Judge Kevin Eide, Comerica are free to act as they see fit to a great extent, but must consult the heirs if any action has a value greater than $2 million. The Nelson sisters said they had not been consulted. However, the organization said in a statement: “In an effort to ensure the preservation of Prince’s audio and visual content, Comerica selected the premier entertainment storage and archive company, Iron Mountain Entertainment Services. On four separate occasions, Comerica discussed the process with the heirs and any suggestion otherwise is not accurate.

“After reviewing the storage conditions at Paisley Park and out of concern regarding the consequences of a fire or other loss at the facility, Comerica determined that it was necessary to transfer the audio and visual content to a secure location where all of the original content could be securely stored and digitized as a safeguard against the destruction or loss of any original content.”

The move to Iron Mountain gained a vote of support from Dave Hampton, who’s previously been technical director at Paisley Park and with Hancock Music in Los Angeles. He told The Prince Podcast that the $200 million valuation was an “unofficial way to curate legacy holding” because no one had yet investigated the archive to establish what was in it. “The first thing you do is secure assets,” he said. “Iron Mountain, the entire entertainment industry use them.” Describing that firm’s environment as a safe “laboratory” where items could be inspected with minimal risk of damage, he added of the Paisley Park vault: “It has a door and kinda like what you see in a bank. It is not a laboratory. I would want to open it up in a lab. Then you can figure out what you can do, and you don’t devalue the potential assets."